Disability discrimination.
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Architectural Accessibility↗
Biomedical subjects
N Markham
Publications and source records attributed to N Markham.
Evaluation of fungal growth on cellulose-containing and inorganic ceiling tile.
Buildings with poor indoor air quality (IAQ) frequently have many areas with surface fungal contamination. Studies have demonstrated that certain fungal genera (e.g., Cladosporium, Penicillium, and Stachybotrys) are able to grow on building materials such as wallpaper, drywall, and ceiling tiles, particularly after water damage has occurred. Due to the increasing awareness of sick building syndrome (SBS), it has become essential to identify building materials that prevent the interior growth of fungi. The objective of this study was to identify building materials that would not support the growth of certain fungal genera, regardless of whether an external food source was made available. The growth of three fungal genera (Cladosporium, Penicillium, and Stachybotrys) was evaluated on cellulose-containing ceiling tile (CCT) and inorganic ceiling tile (ICT). Both types of ceiling tile were exposed to environmental conditions which can occur inside a building. Our results show that ICT did not support the growth of these three fungal genera while CCT did. Our data demonstrate that ICT could serve as an ideal replacement for CCT.
Cellulose↗
Comparison of telomerase activity and GSTP1 promoter methylation in ejaculate as potential screening tests for prostate cancer.
New diagnostic tools are needed for the early detection of prostatic cancer. The molecular detection of prostate cancer cells in ejaculates was evaluated using complementary PCR-based methods. LNCaP cells, a cell line derived from prostatic carcinoma, were spiked into normal seminal ejaculates and the prostatic epithelial component of the specimens was isolated by immunomagnetic bead sorting, using a monoclonal antibody to prostate-specific membrane antigen (PSMA). Ejaculates from nine patients with a recent diagnosis of prostate cancer were processed in a similar fashion, using LNCaP-spiked aliquots as an internal positive control. Telomerase expression was evaluated by the telomeric repeat amplification protocol (TRAP) and glutathione S-transferase gene promoter (GSTP1) hypermethylation was evaluated by methylation-sensitive restriction endonuclease digestion and PCR amplification. Telomerase activity was detected in LNCaP cells recovered from normal seminal ejaculates but was not found in all nine samples from patients with prostate cancer. The sensitivity of GSTP1 analysis was similar to telomerase analysis for the detection of LNCaP cells from normal ejaculate samples but was positive in ejaculates from four out of nine patients with prostate cancer. GSTP1 DNA methylation status is more sensitive than telomerase analysis for the detection of malignant cells in seminal ejaculates from patients with prostate cancer.
DNA Methylation↗
Role of neuronal nitric oxide synthase in regulation of vascular and ductus arteriosus tone in the ovine fetus.
Nitric oxide (NO) is produced by NO synthase (NOS) and contributes to the regulation of vascular tone in the perinatal lung. Although the neuronal or type I NOS (NOS I) isoform has been identified in the fetal lung, it is not known whether NO produced by the NOS I isoform plays a role in fetal pulmonary vasoregulation. To study the potential contribution of NOS I in the regulation of basal fetal pulmonary vascular resistance (PVR), we studied the hemodynamic effects of a selective NOS I antagonist, 7-nitroindazole (7-NINA), and a nonselective NOS antagonist, N-nitro-L-arginine (L-NNA), in chronically prepared fetal lambs (mean age 128 +/- 3 days, term 147 days). Brief intrapulmonary infusions of 7-NINA (1 mg) increased basal PVR by 37% (P < 0.05). The maximum increase in PVR occurred within 20 min after infusion, and PVR remained elevated for up to 60 min. Treatment with 7-NINA also increased the pressure gradient between the pulmonary artery and aorta, suggesting constriction of the ductus arteriosus (DA). To test whether 7-NINA treatment selectively inhibits the NOS I isoform, we studied the effects of 7-NINA and L-NNA on acetylcholine-induced pulmonary vasodilation. The vasodilator response to acetylcholine remained intact after treatment with 7-NINA but was completely inhibited after L-NNA, suggesting minimal effects on endothelial or type III NOS after 7-NINA infusion. Western blot analysis detected NOS I protein in the fetal lung and great vessels including the DA. NOS I protein was detected in intact and endothelium-denuded vessels, suggesting that NOS I is present in the medial or adventitial layer. We conclude that 7-NINA, a selective NOS I antagonist, increases basal PVR, systemic arterial pressure, and DA tone in the late-gestation fetus and that NOS I protein is present in the fetal lung and great vessels. We speculate that NOS I may contribute to NO production in the regulation of basal vascular tone in the pulmonary and systemic circulations and the DA.
Acetylcholine↗
Minimising the impact of visual impairment. From October this will have to be done to conform to the law.
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Humans↗
Efficient human IFN-gamma expression in the mammary gland of transgenic mice.
Two hybrid genes (BLG-HuIFN-gamma2 and BLG-HuIFN-gamma3) were constructed on the basis of sheep beta-lactoglobulin (BLG) and human interferon-gamma (HuIFN-gamma) gene sequences. They were used to direct HuIFN-gamma synthesis in the mammary gland of transgenic mice. HuIFN-gamma was efficiently produced in the mammary gland of transgenic mice. BLG-HuIFN-gamma2 transgenic females expressed HuIFN-gamma in the milk at concentrations up to 570 mg/ml, and BLG-HuIFN-gamma3 transgenic females expressed up to 350 mg/ml. All females carrying the BLG-HuIFN-gamma3 gene expressed HuIFN-gamma in their milk. No significant changes were observed in the HuIFN-gamma expression level during the lactation period. Using RT-PCR analysis, ectopic expression for both hybrid genes was found in transgenic mice. Despite ectopic expression of HuIFN-gamma in transgenic mice, their development and pregnancy were normal. The heritability of the HuIFN-gamma expression level in milk was demonstrated up to the F2 generation. This work demonstrates that hybrid genes have the potential to develop in transgenic domestic animals producing HuIFN-gamma in milk.
Animals↗
Part I. Telomerase levels in human metastatic brain tumors show four-fold logarithmic variability but no correlation with tumor type or interval to patient demise.
Telomerase expression has been found in the majority of human neoplasms at their primary sites and, in some tumor types, has been correlated with patient prognosis. In part one of this two-part study, we investigated whether telomerase was expressed ubiquitously in metastases to the brain and whether varying levels of expression existed or correlated with patient prognosis. A second aim of this study was to acquire data on brain metastases preliminary to the investigation of whether the telomerase assay could be used for the detection of tumor cells in cerebrospinal fluid (CSF). We investigated 35 brain metastases utilizing the sensitive telomeric repeat amplification protocol (TRAP) assay coupled with densitometric quantitation of telomerase levels on frozen, banked tissue specimens. Specimens metastatic to the brain analyzed in this study included melanoma, adenocarcinoma, hepatocellular carcinoma, germ cell neoplasm, squamous cell carcinoma, osteogenic sarcoma, and secondary lymphoma. Telomerase was found in 32 of 35 metastases. Quantitation of the telomerase products showed a fourfold logarithmic variation, following standardization of protein concentrations. Levels of telomerase expression showed no statistical correlation with either tumor subtype or interval from date of procedure to patient demise. Interestingly, in two patients with two metastatic samples each taken at discordant times, the telomerase levels were higher in the metastasis specimen taken closer to the time of demise. This suggests a possible increase in telomerase level within a given patient's neoplasm as the disease became more advanced, although too few cases were available to reach a firm conclusion in this regard. We conclude that most brain metastases express telomerase, albeit at widely varying levels, which are not clearly correlated with patient survival. These results influence the potential utility of telomerase analysis for the detection of small numbers of metastatic tumor cells in CSF, as addressed in the companion manuscript.
Adult↗
When big may not be beautiful
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Journal Article↗
Detection of telomerase expression in fine-needle aspirations and fluids.
The cytologic examination of fine-needle aspirates and fluid specimens is plagued by a persistent false negative rate. The rate of false negative results will be decreased if sensitive molecular assays can be developed to detect cytologically malignant cells. The current study investigated telomerase expression as a potential marker of malignancy, using the telomeric repeat amplification protocol (TRAP) in fine-needle aspirates and fluid specimens. TRAP was performed on 24 fine-needle aspirate and 24 fluid specimens from different body sites and of different histological diagnoses. We found that 6 of 12 fine-needle aspirate specimens that were cytologically positive for malignant cells expressed telomerase activity, while no specimens that were cytologically suspicious for malignancy, atypical, or negative tested positive for telomerase activity. Of the fluid specimens, 4 of 6 cytologically positive cases and 1 of 18 cytologically negative cases expressed telomerase. Seven of eight telomerase negative, cytologically positive specimens contained only rare malignant cells in a very bloody background. Peripheral blood contamination is a possible pitfall in the TRAP assay, as applied in the current study, because the assay is standardized to protein concentration that may be derived from lysed red blood cells. We conclude that with further technical refinement, the TRAP assay could become a useful adjunct in the cytologic examination of fine-needle aspirates and fluid samples.
Biomarkers, Tumor↗
Amelogenin dosage compensation in carcinoma of colon, lung, liver and kidney, is not a marker of clonality in males.
The analysis of patterns of X-chromosome inactivation is becoming increasingly utilized as a marker of clonal composition of tissues from women. To date, however, no analogous system has been found for the study of clonality in tissue from men. In the current study, the methylation patterns for portions of the amelogenin genes are tested, which are encoded on both the X- and Y-chromosome (AMGX and AMGY). The polymerase chain reaction (PCR) was used to amplify portions of AMGX and AMGY from genomic DNA of carcinomas of the colon, lung, liver and kidney, as well as from matched normal somatic tissues. The amplification target included Alu I methylation sensitive restriction endonuclease sites as well as a 189 bp sequence which is present in AMGX but is absent in AMGY. Polymerase chain reaction amplification of AMGX and AMGY was successful using genomic DNA from both tumour and normal control tissue in 24 of the 26 cases. Pretreatment of genomic DNA with Alu I blocked amplification of AMGX in all cases from both normal tissue and tumour. This indicates that AMGX and AMGY undergo a non-random pattern of methylation in both normal tissues and in tumours, precluding their use as a marker of clonality. Methylation of Alu I sites in AMGY suggests that the amelogenin genes undergo dosage compensation, which raises the possibility that the expression of amelogenin is not restricted to the development of the tooth bud but may also play some other role in various tissues of the body.
Adenocarcinoma↗
Human acquired naevi are clonal.
Naevi are nearly universal in humans, yet their cellular origin remains obscure. Understanding the cellular and molecular mechanisms involved in naevus development may be important in understanding the pathogenesis of malignant melanoma. This study aimed to discover whether human acquired naevi are premalignant by examining whether they are clonal. To determine clonality naevi were removed and separated into epithelial and naevus cell fractions and the DNA prepared and digested by a methylase-sensitive restriction enzyme. The highly polymorphic X-linked human androgen receptor (HUMARA) gene was then amplified by a polymerase chain reaction and examined by gel electrophoresis and autoradiography. In polyclonal cell populations both alleles are usually seen as two distinct bands, whilst clonal populations yield a single band. Using these techniques 35 junctional naevi, 11 compound naevi and one congenital naevus from 40 women were examined. Of these, 81% (37 out of 47) of the naevi were clonal, while all of the epithelial cell controls were polyclonal. These data are novel and have great importance for understanding the development of human acquired naevi and cutaneous malignant melanoma. Because monoclonality is a marker of neoplasia, or preneoplasia, our data support the hypothesis that common acquired naevi should be considered to be premalignant lesions, similar to colonic polyps. Such lesions may have undergone the first molecular step(s) in the development of cutaneous malignant melanoma. Understanding the events involved may lead to new methods of prevention and treatment.
Clone Cells↗
Detection of human papillomavirus in squamous cell carcinomas of the lung by polymerase chain reaction.
Existing evidence supports the hypothesis that human papillomavirus (HPV) may play an etiologic role in the malignant transformation of squamous epithelial cells. Although HPV DNA has been identified in a high proportion of squamous cell carcinomas (SCC) of the cervix, anorectum, skin, and upper airways, few studies have tested for HPV in SCC of the lung. To confirm the presence of HPV in lung SCC, we tested for HPV DNA extracted from formalin-fixed tissues of 34 patients by polymerase chain reaction (PCR). DNA amplification was performed using HPV L1 consensus sequence primers (MY11 and MY09; Perkin-Elmer Cetus, Norwalk, CT) which recognize a broad spectrum of HPV types including 6, 11, 16, 18, 31, and 33, among many other known types, as well as at least 20 other unidentified types. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization with [32P]-labeled generic HPV probes. HPV DNA positive cases were subsequently analyzed by slot-blot hybridization of the PCR products with specific probes for HPV types 6, 11, 16, 18, and 33. HPV type 18 was detected in two cases, including one case from a 44-year-old female and one from a 64-year-old male, with the remaining 32 cases negative. In situ hybridization for HPV DNA failed to detect HPV types 6/11, 16/18, or 31/33/35 in any of the cases. We conclude that a small proportion of cases of primary pulmonary SCC test positive for HPV type 18 but that the great majority of cases are not associated with HPV.
Adult↗
Telomerase activity in benign and malignant thyroid tumors.
Thyroid nodules are found in 5% to 10% of the population. While these nodules carry only a 5% to 10% risk of malignancy, tests that complement fine-needle aspiration (FNA) cytology in preoperative diagnosis and risk stratification are lacking. Telomerase is a ribonucleoprotein polymerase with activity found in many malignant tissues, but absent from most normal adult tissue. In this study, we have investigated telomerase activity in 24 thyroid tumors, 14 matched adjacent thyroid tissues, and 3 chronic thyroiditis tissue samples. Using a telomeric repeat amplification protocol (TRAP) assay on frozen tissue, telomerase activity was detected in 11 of 20 thyroid carcinomas, including 10 of 14 papillary carcinomas and a Hurthle cell carcinoma. Telomerase activity was not detected in 4 benign adenomas, 3 follicular carcinomas, or a single case each of medullary and anaplastic thyroid carcinoma. Telomerase activity was detected in 3 of 14 samples of adjacent thyroid tissue from patients with thyroid tumors. Interestingly, all 3 cases of adjacent thyroid tissue that tested positive had a moderate to marked degree of chronic inflammation. In addition, 3 of 3 samples from chronic thyroiditis specimens tested positive for telomerase activity. When tumor invasiveness (vascular and/or capsular) was compared with telomerase activity in papillary carcinomas, only 1 of 4 telomerase-negative tumors was invasive, while 6 of 10 of telomerase-positive tumors were invasive. Moreover, 6 of 7 invasive papillary carcinomas had telomerase activity. In summary, this is the first report of telomerase activity in thyroid tissue and nodules. This activity was detected in a large percentage of papillary thyroid carcinomas, but not benign adenomas, follicular carcinomas, or most normal thyroid tissue. Telomerase activity may also correlate with tumor invasiveness. Further studies will focus on larger numbers of tumors, metastatic tissue, and undifferentiated carcinomas, as well as application of this assay to products from fine-needle aspirates as a potential diagnostic and prognostic marker in thyroid neoplasms.
Adenocarcinoma, Follicular↗
Differential telomerase expression in human primary intracranial tumors.
The telomeric repeat amplification protocol was used to detect expression of telomerase in primary intracranial tumors. Expression was confined to high-grade variants; 10 of 19 glioblastoma multiforme tumors and 5 of 5 primitive neuroectodermal tumors showed telomerase activity. Two of 8 anaplastic gliomas (1 anaplastic oligodendroglioma and 1 anaplastic oligoastrocytoma) were positive for telomerase. Of 16 meningiomas tested, only the 2 atypical variants were positive for telomerase. Two hemangiopericytomas of the central nervous system also showed expression of telomerase. Twenty-two pituitary adenomas (including 6 invasive variants), 2 low-grade gliomas, 2 ependymomas, and 8 nonneoplastic brain specimens were negative. It was concluded that expression of telomerase is found in most glioblastoma multiforme tumors; primitive neuroectodermal tumors appeared to be more uniformly positive. Expression of telomerase in atypical variants of meningioma and hemangiopericytomas of the central nervous system correlated with the potential for aggressive local growth and metastases. Despite the invasive tendency of some pituitary adenomas, telomerase was not detected in these tumors, which suggests that other pathways account for their aggressive behavior.
Adolescent↗
Telomerase expression in normal endometrium, endometrial hyperplasia, and endometrial adenocarcinoma.
Telomerase activity has been detected in a broad range of human cancers and its expression could be an important step in tumor progression. Here, telomerase activity by the telomeric repeat amplification protocol in cases of benign endometrium, endometrial hyperplasia, and endometrial adenocarcinoma was tested. Telomerase expression was detected in 13 of 14 cases of proliferative phase endometrium, in 7 of 12 cases of secretory phase endometrium, but was not detected in any of 7 cases of atrophic endometrium. Three of three cases with evidence of luteal phase defect and one of four cases of chronic endometritis also expressed telomerase activity. Hyperplastic endometrium was positive for telomerase in 13 of 17 cases. Telomerase activity was detected in 40 of 48 cases of endometrial adenocarcinoma, which included 36 of 43 cases of endometrioid adenocarcinoma and four of five cases of papillary serous carcinoma. The detection of telomerase in endometrial adenocarcinoma was not associated with either architectural grade, myometrial invasion, or stage. There was statistically significant association, however, between telomerase activity in benign atrophic endometrium versus any endometrial abnormality in women 52 years of age or older.
Adenocarcinoma↗
Analysis of clonality by polymerase chain reaction for phosphoglycerate kinase-1. Heteroduplex generator.
Polymerase chain reaction (PCR) amplification has been used to determine the clonal composition of tissues based on analysis of the pattern of X-chromosome inactivation, but its use has been limited by technical difficulties. This report presents an expedited method to use PCR in the analysis of clonality. The method uses gel electrophoresis of heteroduplexes formed with an artificial heteroduplex generator (HG) and PCR products from the phosphoglycerate kinase-1 (PGK-1) gene from the tissue sections. Amplification was successful in 36 of 37 cases originally diagnosed as endometrial adenocarcinoma. HG analysis of 36 cases confirmed heterozygosity in 12 cases (33.3%). PGK-1 PCR amplification product was obtained from both control and lesional tissue in 10 of the 12 heterozygous cases. Of these 10 cases, seven were shown to consist of clonal cell populations by HG analysis. Two of three cases diagnosed as well-differentiated endometrioid adenocarcinoma were found to be comprised of polyclonal populations of cells. One case produced an anomalous pattern with HG analysis and was shown to be aneuploid by fluorescence in situ hybridization (FISH) with a chromosome X alpha-satellite probe. It is concluded that HG is a useful alternative to restriction fragment length polymorphism (RFLP) analysis of X-chromosome inactivation as a marker of tissue clonality in cases in women.
Adult↗
The thick common bile duct in pyogenic cholangitis.
The paper describes thickening of the wall of the common bile duct in acute pyogenic cholangitis demonstrated by ultrasound. The abnormality appears as a hypoechoic stripe lying internal to the echogenic line of the normal common bile duct. The clinical features of acute cholangitis may be atypical and this new sign should be of value in these difficult cases.
Cholangitis↗
c-myc oncogene expression in colorectal cancer.
The pattern of c-myc gene organization and expression has been examined in resected colonic tumors and in the adjacent normal colon from 15 patients undergoing radical surgery. DNA hybridization showed no evidence of gene amplification or rearrangement. Transcripts of the c-myc messenger ribonucleic acid (mRNA) were elevated up to 32-fold in 12 of 15 tumors. The gene product, p62c-myc, was detected by both immunoblotting and immunohistology using a monoclonal antibody raised against a synthetic peptide immunogen. There was close correlation between c-myc mRNA copy number and p62c-myc abundance. Three well differentiated tumors contained high levels of transcript and protein, whereas four poorly differentiated tumors had the lowest levels. The assay of oncogene products may provide new biologically relevant tumor markers for determining prognosis and guiding treatment.
Aged↗